Thus, showcases of this type must meet various types of requirements, as regards the preservation and entirety of the displayed objects. In addition, obviously, these showcases are required to guarantee the best visibility for the displayed objects.
With the aim of improving visibility, manufacturers of showcases try as much as possible to use transparent material—typically glass—for the walls of the showcases. Besides guaranteeing better visibility of the displayed objects, the extensive use of glass is often desired by the designers of showcases due to the fact that the transparency of the material allows of heightening the visibility of the displayed objects to the maximum.
Thus, showcases with a base surmounted by a box made up of panels are developed; the base houses all the technical components required for guaranteeing that the environment inside the box is protected and thus normally closed by non-transparent walls, which conceal all the technical components; vice versa, the walls of the box are entirely or partially made of glass, for the aforementioned reasons.
The possibility of access into the box, for housing, removal or maintenance of the displayed objects, is normally obtained by providing for that one of the side panels be openable. For such purpose, opening supports of various types are used, which allow the opening by rotation or roto-translation of the panel (more or less complex hinges) or by sliding (sliding guides). Inevitably, these supports cannot be made of transparent material, for robustness reasons, and thus they are made of metal, thus being visible. At the lower part, the opening supports may be easily housed in the base, but at the upper part they are more or less visible between the upper panel and the openable panel. Hence, these supports often jeopardise the efforts of the designers as regards the maximum transparency of the materials; in particular, in the case of showcases wherein the box is made of panels entirely made of glass, the opening supports risk to have a visibility almost comparable to that of the objects displayed in the showcase.
Thus, the problem of making the opening supports the least visible possible arises, though in case of panels made of transparent material.